RAID Types for the A+ Certification Exams

CompTIA A+ Certification All-in-One For Dummies

You will need to know types of RAID for the A+ Certification Exam. RAID (Redundant Array of Inexpensive Disks) is a method of implementing redundancy (duplicated information) on your hard drives — if one disk fails, the other disk(s) can provide the missing information. There are many different levels of RAID, but the following are the only RAID levels pertinent to the A+ Exam:

RAID 0: Disk striping (striped volume). With RAID level 0, the data is split across drives with no data redundancy. RAID level 0 improves read and write performance by writing to multiple drives at the same time. You need a minimum of two drives.
RAID 1: Disk mirroring/duplexing (mirrored volume). With disk mirroring, the data is written to both drives involved in the mirror in order to provide data redundancy. Windows 7 supports disk mirroring.
RAID 5: Disk striping with parity (RAID 5 volume). With RAID 5 volumes, the data is written to multiple drives along with parity information that is used to help recover data if a single drive fails. RAID 5 volumes need a minimum of three disks.
RAID 10: Mirrored disk striping. RAID level 10 is also known as RAID 1+0 because it is a disk striping while mirroring the data written in the stripe.

About This Article

About the book author:

Edward Tetz has worked with computers as a sales associate, support tech, trainer, and consultant. He holds the Cisco CCNA and numerous other certifications, and has provided system and LAN support to both large and small organizations. Ed is coauthor of CompTIA A+ Certification All-in-One For Dummies.

Timothy Warner, MCSE, MCT, A+, is an IT professional, technical trainer, and author.